Core-pulling mechanism for casting dies



1965 L. w. HAMMOND 3,197,825

CORE-PULLING MECHANISM FOR CASTING DIES Filed Sept. 7, 1961 3 Sheets-Sheet l I i i I I l 7/ Q l Ti" 72 w I r l 30 l l I I I I I l I l I I8 LEONARD w. HAMMOND INVENTOR Aug- 3, 1965 1.. w. HAMMOND CORE-PULLING MECHANISM FOR CASTING DIES 3 Sheets-Sheet 2 Filed Sept. 7, 1961 LEONARD W. HAMMOND INVENTOR fln i Byfl w.

Aug. 3, 1965 w. HAMMOND CORE-PULLING MECHANISM FOR CASTING DIES Filed Sept. 7, 1961 3 Sheets-Sheet Z5 LEONARD W. HAMMOND INVENTOR prior to ejection of the cast piece.

conventional die-casting machine.

United States Patent 'Ofi ice 3,197,825 Patented Aug. 3, 1965 3,197,825 COREPULLING MECHANXSM FOR CASTING DIES Leonard W. Hammond, 4985 Lester NE,

Grand Rapids, Mich. Filed Sept. 7, 1961, Ser. No. 136,546 7 Claims. (Cl. 22-93) This invention relates to the construction of casting dies. Cases are frequently encountered where it is desirable to cast articles having openings or recesses. A die constructed to form such articles will have one or more cavities conforming to the exterior shape of the article, and will also have members extending into these cavities to create the openings or recesses. To avoid distortion of the cast pieces in removing them from the die, it is desirable to withdraw the core members out of the cavity evices for pulling cores are well known, and the present invention relates to this general type of equipment.

Most casting dies are provided with devices for ejecting the cast parts, and these devices are normally actuated by existing standard equipment on die-casting machines. In the preferred form of the present invention, the existing standard actuating equipment on the machine is used to perform the dual functions of core-pulling and ejection. A cam mechanism converts the forces applied by the standard actuating system, and creates a movement which can be sequentially related to the movement of the main actuating mechanism. An intermediate member is positioned with respect to the die member by the cams, in the preferred form of the invention, creating a core-pulling action which can be opposite in direction from the ejection movement. Both of these actionsare induced by the motion of the standard actuating mechanism.

The several features of the invention will be analyzed in further detail through an analysis of the particular embodiments illustrated in the accompanying drawings. In the drawings:

FIGURE 1 presents a fragmentary side elevation of .a die-casting machine showing the casting dies and associated actuating equipment.

FIGURE 2 is a fragmentary sectional elevation on an enlarged scale from that of FIGURE 1, and showing the upper section of a die-casting die.

FIGURE 3 presents a fragmentary sectional view showing the lower portion of the die-casting die with the related corepulling and ejection mechanism. FIGURE 3 illustrates the equipment in condition to begin the withdrawal of the cores.

FIGURE 4 presents a sectional elevation on the same scale as that of FIGURES 2 and 3, and showingthe completion of the core-pulling action.

FEGURE 5 presents a sectional elevation on the same scale as that of FIGURES 2, 3, and 4, and showing the completion of the ejection movement removing the cast part from the lower die section.

FIGURE 6 presents a section on the plane 66 of FIGURE 7.

FIGURE 7 presents a plan view of the lower section of the die, with the mold inserts removed.

Referring to FIGURE 1, the drawings illustrate a A group of massive rods such as are indicated at ill and 11 served as guideu'ays for positioning the movable plate 12 with respect to the fixed plate 13. The heavy nuts 14 and 15 secure formed by a conventional hydraulic system.

The main function of the mechanism thus far dethe fixed plate 13 with respect to the rods 10 and 11. The moving plate 12 is positioned by a mechanical linkage generally indicated at'ld, or this function may be perare withdrawn from the bosses 41 and 42.

scribed is to provide for opening and closing the lower die member 17 with respect to the upper die member 18. The mechanism is often arranged horizontally, and upper and lower do not indicate any particular orientation to the vertical. When the two die members are closed, they completely define the casting cavities between them; and when separated, they permit the removal of the cast pieces from the cavities which form them. The main functions of a die-casting machine are to provide the necessary opening and closing movement, and to hold the die members closed with sufiicient force to withstand the tremendous liquid pressure used in the molten material inserted at the point generally indicated at 19. The casting material is pumped into the cavities under pressures often amounting to several thousand pounds per square inch, which creates a tremendous force tending to separate the upper and lower die members. The magnitude of these forces accounts for the general massiveness of the machine. An actuating mechanism generally indicated at 20 is usually incorporated in the machine for applying a to-and-fro movement to the rods 21 and 22 for operating the die structure.

FIGURES 2 and 3 are related views, and show the condition of the equipment when the movable plate 12 has been withdrawn by the linkage 16 to separate the die members 17 and 18. When the die was closed, the alignment between these two sections had been maintained by the pins 23 and 24, and the cast piece 25 is now in condition to have the cores pulled and then be ejected from the die member 17. The mechanism for accomplishing this involves the frame member 26 which is normally fixed with respect to the die member 17 by a group of clamps as are indicated at 27 and 28. This same type of clamp may be used to secure the components of the upper die member, these being indicated at 29 and 3t An intermediate member 31 is associated with the frame 26 by a group of screws, as are indicated at 32 in the drawings. The principal function of these screws is to establish a limit to the freedom of movement of the intermediate member 31 downwardly with respect to the frame 26, as viewed in FIGURES 3, 4, and 5 of the drawings. A fixed path of movement between the intermediate member 31 and the frame 26 is established by the pins 33 and 34 (refer to FIGURE6) which are fixed with respect to the intermediate member 31, and slide in the bearing sleeves 35 and 36 secured to the frame member 26. Similar pins may also be provided as indicated at 37 and 38, similarly received in suitable hearings in the frame 26.

The core rods 39 and 41 have their lower extremities (as shown in FIGURE 3) secured to the intermediate member 31 so that they move axially with it Within bores in the die member 17 which receives them. When in the extended position shown in FIGURE 3, these core rods 39 and 49 extend into the cavities forming holes in the bosses 41 and 42 of the cast member 25. Prior to the ejection of the cast member 25, the core rods 39 and 40 This condition is shown in FIGURE 4.

The mechanism utilized for withdrawing the core rods 39 and 4-6 involves the actuating plate 43 which moves in response to the forces applied by the actuating rods 21 and 22. The plate 43 is provided with projections as indicated at 44 which move through openings in the intermediate member 31. These projections transfer the forces from the plate 43 which are responsible for pulling the cores, and later actuating the ejection mechanism. The

The projections 44 are provided with a shoulder as shown at 47, with the outer end 48 of the earns 45 overhanging the shoulder 47 in the position shown in FIG- URE 3. As the actuating plate 43 moves upwardly, this movement establishes a path of movement of the projections 44 (including the shoulder 47), and the end 48 of the cam is disposed within this path of movement so that the cam is rotated as the actuating plate 43 moves upwardly. Referring to FIGURE 7, the disposition of the cams 45 is such that a portion of the surface of the cams bears against the underside of the portion 26a of the frame member 26. These same conditions exist at the four corners of the die structure. 7

The result of the rotation of the cams is to induce a separation of the intermediate member 31 from the frame member 26 to the position shown in FIGURE 4. The length of the earns 45 and the conformation of the projections 44 are related in such a manner that the completion of a limited degree of separation takes place at the time at which the outer ends of the earns 45 drag over the edge of the shoulders 47, with further upward movement of the projections resulting in sliding the outer ends of the cams along the side surfaces 49 of the projections 44. The separation of the intermediate member 31 form the frame member results iin withdrawing the core rods 39 and 40 into the position shown in FIGURE 4 where they are clear of the cavities forming the bosses 41 and 42 of the cast members 25. The core rods 39 and 49 have formed the holes 50 and 51, respectively, in these bosses.

The Completion of the withdrawal of the core rods 39 and 46 corresponds to the position at which the heads of the screws 32 abut the ends of the recesses 52 in the intermediate member 31. Continued movement of the actuating plate 43 produces the condition illustrated in FIGURE 5. The beginning of this motion corresponds to the showing of FIGURE 4, and it will be noted that the end of the projection 44 is at that moment in contact with the carrier plate 53. This plate slides on the locating pins 54 and 55, and carries with it the ejection pins 5659 which force the bosses 41 and 42 out of their respective cavities in the die member 17. According to usual die casting procedures, a die member of the type indicated at 17 may contain a large number of cavities which are individually formed to produce a complete part. These may be connected by channels commonly referred to as sprues, with the net result that the cast article will contain a variety of the cast parts interconnected by a spoke-like structure in which the central hub is formed by the spreader 6iiwhich diverts the flow of the molded material out into the radiating channels. In addition to the bosses 41 and 42, the cast piece may contain other similar pieces, two of these appearing at 61 and 62 in FIGURE 5, elevated by their respective ejection pins. A central ejection system for elevating the casting near the hub includes the rods 63-66 connected to the bumper plate 67.

Many of the structural details of the die member 17 w ll vary according to the individual preference of the die designer and the die-maker. In the illustrated modification of the invention, the die member 17 includes the sections 17a and 17b having tongue-and-groove engagement with the central block 170. In FIGURE 7, the sections 17a and 17b are removed, with the central block 170 remaining. The base member 68 is secured directly to the moving plate 12 of the die-casting machine by a group of clamps as shown at 69 and 70 in FIGURE 3. A similar group of clamps as shown at 71 and 72 secures the upper, die member to the fixed plate 13. The return of the ejector rods to the position shown FIGURE 3 may be provided by any conventional arrangement, either through springs (not shown) or by the 'action of the liquid pressure. The completion of the casting cycle will involve the withdrawal of the rods 21, accompanied by the movementof the plate 43 back to the position shown in FIGURE 3. The closure of the gap between the frame 26 and the intermediate die member 31 will occur as a result of the closing pressure applied by the linkage of the machine and will re-position the core rods.

It is preferable that the base member 68 be provided with a peripheral shelf 73 which will receive the flange 74 of the actuating plate 43. With this arrangement, the assembly of the components is maintained when the entire die is removed and installed in the machine. To facilitate the movement and alignment of the plate 43 within the central opening in the base member 63, it is preferable to include the guide rods as shown at 75a and 75b in FIGURE 6. These rods reciprocate within aligned bores in the die member 17, the frame 26, and the intermediate member 31.

The particular embodiments of the present invention which have been illustrated and discussed herein are for illustrative purposes only and are not to be considered as a limitation upon the scope of the appended claims. In these claims, it is my intent to claim the entire invention disclosed herein, except as I am limited by the prior art.

I claim:

I. A core-pulling and ejection mechanism for a casting die member having a molding cavity, and also including core means having a portion thereof normally disposed within said cavity and withdrawable therefrom along a particular path of movement, said die member also including ejection means having a direction of movement parallel to the path of Withdrawing movement of said core means, said mechanism comprising: frame means supporting and normally secured to said die memher, said frame means having an opening receiving portions of said ejection means, an intermediate member disposed adjacent to said frame means movable toward and away from said die member in a direction parallel to said path of withdrawing movement, said intermediate member having open portions therein, and said intermediate member being secured to said core means to control the movement thereof; guide means maintaining the path of movement of said intermediate member with respect to said die member; stop means limiting the separation of said intermediate member from said frame means; a base member secured to said intermediate member, said base member having an opening; an actuating plate disposed within said base member opening; projection means secured to said actuating plate and extending through an intermediate member open portion, said projection means having a shoulder adjacent the end thereof opposite from said actuating plate; cam means rotably mounted on said intermediate member in an open portion thereof, said cam means having a portion thereof disposed within the path of relative movement of said shoulder whereby movement of said projection means induces rotation of said cam means, said cam means also having a portion disposed to bear on said frame to induce separation thereof from said intermediate member on rotation of said cam means; a carrier plate movably mounted with respect to said die member and secured to said ejection means, said carrier plate having a portion disposed within the path of relative movement of a portion of said projection means; whereby a stroke of movement of said actuating plate causes said projection means to induce withdrawal of said core means followed by ejecting movement of said ejection means.

2. A core-pulling and ejection mechanism for a casting die member having a molding cavity, and also including core means having a portion thereof normally disposed within said cavity and withdrawable therefrom along a particular path of movement, said die member also including ejection means having a direction of movement parallel to the path of withdrawing movement of said core means, said mechanism comprisnig: frame means supporting and normally secured to said die member, said frame means having an opening receiving portions of said ejection means; an intermediate member disposed adajacent to said frame means movable toward and away from said die member in a direction parallel to said path of withdrawing movement, said intermediate member having open portions therein, and said intermediate member being secured to said core means to control the movement thereof; guide means maintaining the path of movement of said intermediate member with respect to said die member; a base member secured to said intermediate member, said base member having an opening; an actuating plate disposed within said base member opening; projection means secured to said actuating plate'and. extending through an intermediate member open portion, said projection means having a shoulder adjacent the end thereof opposite from said actuating plate; cam means rotatably mounted on said intermediate member in an open portion thereof, said cam means having a portion thereof disposed within the path of relative movement of said shoulder whereby movement of said projection means induces rotation of said cam means, said cam means also having a portion disposed to bear on said frame to induce separation thereof from said intermediate member on rotation of said cam means; a carrier plate movably mounted with respect to said die member and secured to said ejection means, said carrier plate having a portion disposed within the path of relative movement of a portion of said projection means; whereby a stroke of movement of said actuating plate causes said projection means to induce withdrawal of said core means followed by ejecting movement of said ejection means. r

3. A core-pulling and ejection mechanism for a casting die member having a molding cavity, and also including core means having a portion thereof normally disposed within said cavity and withdrawable therefrom along a particular path of movement, said die member also including ejection means having a direction of movement parallel to the path of withdrawing movement of said core means, said mechanism comprising: an intermediate member disposed adjacent to said die member and movable toward and away from said die member in a direction parallel to said path of withdrawing movement, said intermediate member having open portions therein, and said intermediate member being secured to said core means to control the movement thereof; guide means maintaining the path of movement of said intermediate member with respect to said die member; a base member secured to said intermediate member, an actuating plate moveably mounted with respect to said base member; projection means secured to said actuating plate; cam means rotatably mounted on said intermediate memher, said cam means havin a portion thereof disposed within the path of relative movement of a portion of said projection means whereby movement of said projection means induces rotation of said cam means, said cam means also having a portion disposed to bear on said die member to induce separation thereof from said intermediate member on rotation of said cam means; a carrier plate movably mounted with respect to said die mem ber with said ejection means, said carrier plate having a portion disposed within the path of relative movement of a portion of said projection means; whereby a stroke of movement of said actuating plate causes said projection means to induce withdrawal of said core means followed by ejecting movement of said ejection means.

4. A core-pulling mechanism for a casting die member having a molding cavity, and also including core means having a portion thereof normally disposed within said cavity and withdrawable therefrom along a particular path of movement said mechanism comprising: frame means supporting and normally secured to said die member; an intermediate member disposed adjacent to said frame means movable toward and away from said die member in a direction parallel to said path of withdrawing movement, said intermediate member having open portions therein, and said intermediate member being secured to said core means to control the movement thereof; guide means maintaining the path of movement of said intermediate member with respect to said die member; stop means limiting the separation of said intermediate member from said frame means; a base member secured to said intermediate member, said base member having an opening; an actuating plate disposed within said base member opening; projection means secured to said actuating plate and extending through an intermediate member open portion, said projection means having a shoulder adjacent the end thereof opposite from said actuating plate; and cam means rotatably mounted on said intermediate member in an open portion thereof, said cam means having a portion thereof disposed within the path of relative movement of said shoulder whereby movement of said projection means induces rotation of said cam means, said cam means also having a portion disposed to bear on said frame to induce separation thereof from said intermediate member on rotation of said cam means.

5. A core-pulling mechanism for a casting die member having a molding cavity, and also including core means having a portion thereof normally disposed within said cavity and withdrawable therefrom along a particular path of movement said mechanism comprising: frame means supporting and normally secured to said die member; and intermediate member disposed adjacent to said frame means movable toward and away from said die member in a direction parallel to said path of withdrawing movement, said intermediate member having open portions therein, and said intermediate member being secured to said core means to control the movement thereof; guide means maintaining the path of movement of said intermediate member with respect to said die member; a base member secured to said intermediate member, said base member having an opening; an actuating plate disposed within said base member opening; projection means secured to said actuating plate and extending through an intermediate member open portion; and cam means rotatably mounted on said intermediate member in an open portion thereof, said cam means having a portion thereof disposed within the path of relative movement of a portion of said projection means whereby movement of said projection means induces rotation of said cam means, said cam means also having a portion disposed to bear on said frame to induce separation thereof from said intermediate member on rotation of said cam means.

6. A core-pulling mechanism for a casting died member having a molding cavity, and also including core means having a portion thereof normally disposed within said cavity and withdrawable therefrom along a particular path of movement, said mechanism comprising: an intermediate member disposed adjacent to said die member and movable toward and away from said die member in a direction parallel to said path of withdrawing movement, said intermediate member being secured to said core means to control the movement thereof; guide means maintaining the path of movement of said intermediate member with respect to said die member; a base member secured to said intermediate member; an actuating plate movably mounted with respect to said base member; projection means secured to said actuating plate, said projection means having a shoulder adjacent the end thereof opposite from said actuating plate; and cam means rotatably mounted on said intermediate member in an open portion thereof, said cam means having a portion thereof disposed within the path of relative move ment of said shoulder whereby movement of said portion means induces rotation of said cam means, said cam means also having a portion disposed to bear on said die member to induce separation thereof from said intermediate member on rotation of said cam means.

7. A core-pulling mechanism for a casting die having a molding cavity, and also including core means having a portion thereof normally disposed within said cavity and withdrawable therefrom along a particular path of movement, said mechanism comprising: an intermediate member disposed adjacent to said die member and movable toward and away from said die member in a direction parallel to said path of Withdrawing movement, said intermediate member being secured to said core means to control the movement thereof; guide means maintaining the path of movement of said intermediate member with respect to said die member; a base member secured to said intermediate member; an actuating plate moveably mounted with respect to said base member; projection means secured to said actuating'plate; and a cam means rotatably mounted on said intermediate member, said cam means having a portion thereof disposed within the path of relative movement of a portion of said projection means whereby movement of said projection means induces rotation of said cam means, said cam means also having a portion disposed to bear on said die member to induce separation thereof from said intermediate member on rotation of said cam means.

References Cited by the Examiner UNITED STATES PATENTS 2,704,388 3/55 West et a1 2294 7 2,783,501 3/57 Kutnik 22-94 WILLIAM J. STEPHENSON, Primary Examiner.

RAY K. WINDHAM, Examiner. 

7. A CORE-PULLING MECHANISM FOR A CASTING DIE HAVING A MOLDING CAVITY, AND ALSO INCLUDING CORE MEANS HAVING A PORTION THEREOF NORMALLY DISPOSED WITHIN SAID CAVITY AND WITHDRAWABLE THEREFROM ALONG A PARTICULAR PATH OF MOVEMENT, SAID MECHANISM COMPRISING: AN INTERMEDIATE MEMBER DISPOSED ADJACENT TO SAID DIE MEMBER AND MOVABLE TOWARD AND AWAY FROM SAID DIE MEMBER IN A DIRECTION PARALLEL TO SAID PATH OF WITHDRAWING MOVEMENT, SAID INTERMEDIATE MEMBER BEING SECURED TO SAID CORE MEANS TO CONTROLL THE MOVEMENT THEREOF; GUIDE MEANS MAINTAINING THE PATH OF MOVEMENT OF SAID INTERMEDIATE MEMBER WITH RESPECT TO SAID DIE MEMBER; A BASE MEMBER SECURED TO SAID INTERMEDIATE MEMBER; AN ACTUATING PLATE MOVEABLY MOUNTED WIHT RESPECT TO SAID BASE MEMBER; PROJECTION MEANS SECURED TO SAID ACTUATING PLATE; AND A CAM MEANS ROTATABLY MOUNTED ON SAID INTERMEDIATE MEMBER, SAID CAM MEANS HAVING A PORTION THEREOF DISPOSED WITHIN THE PATH OF RELATIVE MOVEMENT OF A PORTION OF SAID PROJECTION MEANS WHEREBY MOVEMENT OF SAID PROJECTION MEANS INDUCES ROTATION OF SAID CAM MEANS, SAID CAM MEANS ALSO HAVING A PORTION DISPOSED TO BEAR ON SAID DIE MEMBER TO INDUCE SEPARATION THEREOF FROM SAID INTERMEDIATE MEMBER ON ROTATION OF SAID CAM MEANS. 